Connery for me. Moore went on to long (although he came out with some classic 1 liners) I never took to dalton, Brosnans reign started well then went downhill after TND, And Craig is terrific, but his films are not great.
To add to what an above poster said, I think Lazenby comes in for some unfair stick regarding OHMSS. People have to remember that it was his first ever major acting role. A Silly plot line awell.